The present invention relates to bladder propellant (or fuel) tank assemblies and manufacturing methods.
Propellant tanks with internal bladders are frequently utilized in aerospace applications, particularly for use with rocket engines for space vehicles. In general, these bladder propellant tanks store propellant (e.g., hydrazine) to one side of the internal bladder, and can admit a pressurized gas (e.g., helium) at the other side of the internal bladder to force the propellant out of the tank through an outlet port. These bladder propellant tanks can be formed from two aluminum or titanium half-domes welded together. The process typically used to weld the two half-domes together involves making three electron beam (EB) welds. However, it is desired to provide an assembly and manufacturing method that does not require electron beam welding while providing a bladder tank at lower cost and with less weight.